For a drive force control for vehicle, an method has been conventionally widely adopted which controls an output of an internal combustion engine based on a depression amount of an accelerator pedal and, on the other hand, controls a speed ratio of an automatic transmission based on the depression amount of the accelerator pedal and a vehicle speed. According to this conventional method, the engine and the transmission are independently controlled according to individual target values.
In contrast, JP2001-328462A, published in 2001 by the Japan Patent Office, proposes a powertrain torque demand (PTD) control for setting a target vehicle drive force from a depression amount of an accelerator pedal and a vehicle speed and integrally controlling a speed ratio of an automatic transmission and a torque of an internal combustion engine to achieve a target vehicle drive force.